Reflections of a CD Burn

I have always been impressed with the
hosts on home-builder/handyman television shows: they seem to be
able to complete whole projects in 30 minutes. Have you tried
building an Adirondack chair in 30 minutes?That same project would
take me, a measure twice, cut once too short, find more material
computer geek, (insert formula) 1h x 30days x 3months =
no-chair-yet amount of time. But in 30 minutes, the TV host is
usually sitting out in front of the shop with two finished
Adirondack chairs, drinking iced tea with his buddy.This article is the made-for-television, Adirondack chair
version of how to burn a CD. What won't be obvious here is the two
weeks, Christmas vacation 2001, that I spent off air, researching,
testing and editing, to produce both the CDs and the
article.Roll cameraYour buddy wants you to make him audio CDs he can play in his
truck. Therefore, you will take MP3 files and burn them to a CD in
a format that can be played on the truck CD player or any other
one. This project was initiated by my home handyman,
jack-of-all-trades, chair-building friend; I'll just call him
buddy. Oh yeah, did I mention you want to burn this CD using a PC
running Linux.RequirementsHardware (What I
used)

• 64MB RAM Pentium 233MMX PC
• Sony CRX140S (SCSI) CD-ROM burner
• AVA-1505 AT-to-SCSI Host adapter

Software (What you
need)

• Red Hat Linux 7.2 server installation, with a
  window manager (GNOME/KDE) GUI support.

Okay, this can be made to work with others Linux
distributions or your own from source. I was hoping you would use
Red Hat because I have Red Hat stocks in my retirement plan.

• Cdrtoaster-1.12 application software.

Check out Ian Kjos' Cdrtoaster program at
www.jump.net/~brooke/cdrtoast.
Stop CameraCdrtoaster is a GUI frontend program that produces syntax
critical command-line strings that process the input MP3 file and
actually burn the audio CD. The actual CD burning is done by a
program called Cdrecord; more on that later. Remember the 30-minute
show on building a chair? This is part where all the stuff that
needs to be done to make the host's chair look good is now done by
you. You need to install Linux on a PC that has all the CD-burning
components (i.e., CD/writer) working. Without a working CD burner
this article becomes reading room material.If you do a cat /proc/interrupts at the
command line and don't see an interrupt assigned to the SCSI card,
go directly to jail, do not pass go and do not collect $200. It
took some of that two-week vacation I mentioned before for me to
solve this problem on my computer. This is the output after it was
working:

[root@burner root]# cat /proc/interrupts
           CPU0
  0:    3770057          XT-PIC  timer
  1:       2317          XT-PIC  keyboard
  2:          0          XT-PIC  cascade
  4:      29089          XT-PIC  serial
  5:      18925          XT-PIC  soundblaster
  8:          1          XT-PIC  rtc
 10:         17          XT-PIC  aha152x <--------Houston we have ignition!
 11:      23053          XT-PIC  eth0
 14:          1          XT-PIC  ide0
 15:     118631          XT-PIC  ide1
NMI:          0
ERR:          0

In order to get the card working in this machine, I did two
things.Thing 1: I edited the /etc/modules.conf file to include
alias scsi aha152x. This is the driver required
to support this old ISA SCSI card.Thing 2: I edited the /etc/rc.d/rc.local file to include
modprobe scsi aha152x=0x140,10,7,1. This line
assigns a port address, interrupts, SCSI IDs and other stuff to the
device.Roll CameraConfirm your CD-RW is recognized by Cdrecord by entering the
following from the command line:

[root@burner root]# cdrecord -scanbus
Cdrecord 1.10 (i686-pc-linux-gnu) Copyright (C) 1995-2001 Jorg Schilling
Linux sg driver version: 3.1.20
Using libscg version 'schily-0.5'
scsibus0:
        0,0,0     0) *
        0,1,0     1) *
        0,2,0     2) *
        0,3,0     3) *
        0,4,0     4) *
        0,5,0     5) *
        0,6,0     6) 'SONY    ' 'CD-RW  CRX140S  ' '1.0e' Removable CD-ROM <--Houston we have lift off!
        0,7,0     7) *

/usr/bin/cdrecord is the actual program that does the CD
buring. Remember Cdrtoaster is the GUI frontend that will speak
Cdrecord's syntax-critical language.Install the Cdrtoaster-1.12 application in your home
directory and do a permissions change to make the file
executable.Stop CameraI put the application in /home/username and did the entered
chmod 700 cdrtoaster-1.12 from the command line.
The type usermod -G cdwrite username. This
second command makes the user a member of the group cdwrite and
gives the user sufficient permissions to burn a CD.Roll CameraCongratulations you are ready to burn!BurningStart the Cdrtoaster application, select the files you wish
to burn to a CD, select Audio CD, remove the selection for dummy
burn (hey remember, cameras are rolling), insert high quality CD
showing label to camera as disk is inserted and select Have a cook
off.Stop cameraIf your first audio CD burn sounds like a never before
released album of the Chipmunks, welcome to the fan club. Hey
didn't you see the part of the show where he told you that how the
MP3 are created will effect how the audio sounds after it is
processed by Cdrtoaster? Maybe that part landed on the cutting room
floor.Cdrtoaster does two things:Thing 1: MP3 files are converted
to WAV format for audio CDs, and this line is taken right from the
cdrtoaster-1.12 script.exec mpg123 -s $orig | sox -t raw -w -s -c 2 -r
44100 - -t wav $tempfile > &/dev/nullIf you drop the exec command and replace the variables with
filenames, the command can then be executed from the command line.
If you manually convert one of your MP3 to a WAV file and test the
sound before burning, you may not have to join the fan club.The industry standard (techie term Red Book) specifies the
audio must in be in a format of 44100Hz, 16-bit PCM, 2-channel,
big-endian. If the source material for that MP3 was not recorded at
44100Hz, audio errors are created when Cdrtoaster does the
conversion to WAV files using mpg123.The MP3s I was provided were not formatted to the standard.
To prevent the creation of Chipmunk albums, I did my own audio
conversion from the command line. I then used Cdrtoaster to burn my
pretreated files. The following is the command I used:mpg123 -s sample.mp3 | sox -t raw -w -s -c2 -r 22050
- -t wav -r 44100 sample.wavImportant fact: Linux does
not appreciate you filling up certain partitions. WAV files
produced from this command may be ten times as large as the
original MP3 file. If you run this command from a looping script
(execute once to do all the files in a directory at once), Gigs of
drive space get eaten up real fast, so make sure you have
sufficient drive space to do the conversion.Thing 2: burn cd.cdrecord -v -eject dev=/dev/sg0 speed=2 -audio -pad
/home/username/sample1.wavI usually purchase my blank CDs by the "cord" at the local
discount store. The novelty of colored CD coasters and computers
with no covers has worn off in my household. For this reason I set
the burn speed lower and put computer covers back on after working
on them. Did I mention my home network has six computers?You can view the man pages for the command files, like
Cdrecord, mpg321(this is not a typing error) and sox if you want to
do some research. Note that Cdrtoaster uses mpg123. mpg123 is
installed with Red Hat 7.2, but you don't get the valuable man
pages. The included man pages are for the GPL-lookalike, but
Cdrtoaster scripts can be modified to use the new file. I was
staying focused on the goal, buddy with truck that has CD
player.Roll CameraBack from a commercial, you are sitting in your buddy's truck
playing the audio CD you just burned while credits are queuing by.
Hey are those two Adirondack chairs I see in the back of that
truck. Enjoy.Sean D. Conway is a former
college instructor turned Network System Specialist for a regional
telecommunications company in Canada.

email: seconway@mts.net